This invention relates in general to improvements in log buildings and deals more particularly with improved means for mounting the windows in such a building. A building of the type with which the present invention is concerned has exterior walls formed by horizontally extending log courses arranged in vertically stacked relation. Conventional windows of double-hung or casement type are mounted in window openings formed in the log walls. Such walls are prone to settle due to log shrinkage and because each of the logs which comprise the walls must carry the weight of all of the logs thereabove. Such wall settlement may cause changes in the vertical dimensions of window openings resulting in damage to the windows or separation of the joints between adjacent logs which define the window openings necessitating window removal and replacement. The present invention is concerned with these problems.